Thanks for all the replies. I think that with the equipment to hand it would be worth doing,........ It certainly seems as if I am not the only one that thinks of these things (my beloved was shocked that I even considered it). I like the idea of using an airline to pressurise the tank to avoid drinking diesel - (note to self - must get an air line). I tried to look for the fuel pipes, but could not move around easily under the car (note to self - must by some wheel ramps).
As it happens, the scrap man offerred me more than scrap value for the car, and I pushed him up another £50 for the diesel. He probably got a good deal - he will tart it up and sell it on at a profit - that is part of his job. But I will not have to deal with tire-kickers, or worry about the upcoming costs (include cam belt, seatbelt, window seals, and possibly PAS which played up a little last winter). I am glad that the car will get some more use, and equally glad that I did not sell it to a private buyer in a town this small........
Next time I will run around close to empty when thinking of changeing cars.